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/*
* lbcd load module to check LDAP server.
*
* Written by Larry Schwimmer
* Copyright 1997, 1998, 2007, 2008, 2012
* The Board of Trustees of the Leland Stanford Junior University
*
* See LICENSE for licensing terms.
*/
#include <config.h>
#include <portable/system.h>
#include <errno.h>
#include <signal.h>
#include <sys/time.h>
#include <sys/wait.h>
#include <server/internal.h>
#include <modules/modules.h>
/* We test the LDAP server by running ldapsearch and checking its result. */
#ifdef PATH_LDAPSEARCH
# define LDAP_EXEC execl
#else
# define LDAP_EXEC execlp
# define PATH_LDAPSEARCH "ldapsearch"
#endif
/*
* Probe the LDAP server. We do an anonymous ldapsearch for a subtree search
* of cn=current,cn=connections,cn=monitor for the monitorCounter attribute.
* This logic may be somewhat specific to OpenLDAP and returns the number of
* active connections so that we can generate a more accurate load. Returns
* the number of connections on success and -1 on failure.
*/
#ifdef HAVE_LDAP
static int
probe_ldap(const char *host, int timeout)
{
int retval = 0;
int fd[2];
if (pipe(fd) == 0) {
pid_t child;
child = fork();
if (child < 0)
return -1;
else if (child == 0) {
close(fd[0]);
close(2);
if (fd[1] != 1) {
dup2(fd[1], 1);
close(fd[1]);
}
LDAP_EXEC(PATH_LDAPSEARCH, "ldapsearch", "-x", "-LLL",
"-h", host ? host : "localhost",
"-b", "cn=current,cn=connections,cn=monitor",
"-s", "sub", "monitorCounter", (char *) 0);
exit(1);
} else {
int stat_loc;
FILE *fp;
char buf[128];
close(fd[1]);
fp = fdopen(fd[0], "r");
if (fp == NULL)
return -1;
while (waitpid(child, &stat_loc, timeout) < 0)
if (errno != EINTR) {
fclose(fp);
if (kill(SIGTERM, child) == -1)
kill(SIGKILL, child);
return -1;
}
if (WIFEXITED(stat_loc)) {
if (WEXITSTATUS(stat_loc) != 0) {
fclose(fp);
return -1;
}
} else {
if (kill(SIGTERM, child) == -1)
kill(SIGKILL, child);
fclose(fp);
return -1;
}
while (fgets(buf, sizeof(buf), fp) != NULL) {
if (strncmp(buf, "monitorCounter: ", 16) != 0)
continue;
retval = atoi(buf + 16);
break;
}
fclose(fp);
}
} else {
return -1;
}
return retval;
}
/*
* The module interface with the rest of lbcd. Converts the return code to 0
* (success) or -1 (failure).
*/
int
lbcd_ldap_weight(uint32_t *weight_val, uint32_t *incr_val UNUSED, int timeout,
char *portarg UNUSED)
{
*weight_val = (uint32_t) probe_ldap("localhost", timeout);
return (*weight_val == -1) ? -1 : 0;
}
#endif /* HAVE_LDAP */
/*
* Test routine.
*/
#ifdef MAIN
int
main(int argc, char *argv[])
{
int status;
status = probe_ldap(argv[1], 5);
if (status == -1)
printf("ldap service not available\n");
else
printf("ldap server %s has %d connections.\n",
argv[1] ? argv[1] : "localhost", status);
return status;
}
#endif
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